Utilization of Raman Spectroscopic Techniques for Forensic Science Applications

In the field of forensic science, it is important to have reliable, accurate, and nondestructive testing methods for evidence collection and testing. Current methods, such as gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC), are destructive to evidence and require lengthy sample preparation. Because of its nondestructive nature, specificity, and portability, Raman spectroscopy has been increasingly improving forensic science. The goal of this work is to expand on the growing pool of knowledge of forensics related Raman applications.

One problem that has plagued forensic scientists for years is how to accurately identify the time since death, or post-mortem interval. Scientists have been able to estimate time since death based on physical evidence and environmental factors, but it has notoriously proven difficult to quantify this information. It has been difficult for scientists to find a biomarker of post-mortem interval. Herein, we present a Raman study of amino acids to determine possible biomarkers. We also present the first use of spatially offset Raman spectroscopy (SORS) to identify potential biomarkers of post-mortem interval through a whole bovine eye.

Another area where Raman spectroscopy has previously shown to be useful previously is in the study of bone composition. Although the chemical composition of bone is well understood, how bone composition changes through the bone healing process is not as well understood. Here we show the potential of SORS to be used as a tool to estimate the age of bone fractures by changes in chemical composition over time. It is our hope that in the future this method could be developed further and used to age bone fractures of child abuse victims in vivo.

The further development of the results of this work could lead to faster, portable, specific, and nondestructive determination of forensically relevant information from in vivo samples. Successful development of these techniques could revolutionize the field of forensic evidence analysis by improving chemical specificity and providing a portable technique with rapid, reliable results.